Category Best Practice for eCommerce site

Does anyone know of any research that provides insight into the
recommended number of categories and subcategories a store should
contain?

I know best practice is to keep the options simple and easy to scan
(7-12), but for an ecommerce site it tends to be whatever is
necessary to adequately cover the breadth of your products. I need
some evidence on where to draw the line.

Thanks

Comments

13 Jan 2010 - 6:23am

Paul Bryan

2008

Hi Paul,

I have reviewed web analytics and interviewed customers for a number
of top e-commerce sites. Their data is proprietary, but I can relate
some high level findings that may help your design decision-making.

The use of product sub-categories to navigate is highly category
dependent. For example, a high percentage of customers click through
categories for products that are primarily evaluated through their
features, like appliances and electronics. On the other hand,
customers prefer images for products where style issues are the chief
decision criteria, like clothes and patio furniture. For clothes,
customers typically first look for a visual that represents the
general category of clothing they are interested in, which is a
semantic approach to wayfinding even though it involves images,
because the images are merely representatives of the taxonomy
category. Beyond that level they are usually scanning visuals rather
than using sub-category navigation. For patio furniture, customers
often ignore text altogether and start clicking on pictures that they
think will give them an idea of the available assortment that matches
their style filter.

I've seen reports that over 50% of users will use search instead of
clicking through categories. This may be true in qualitative studies,
but I don't see anywhere near that percentage in the e-commerce
analytics I've reviewed, for sites receiving upwards of a million
visitors per month. It's usually under 20% at the category level.

So what's the point? The number of categories that customers are
willing to scan through to find what they're looking for depends on
the category of merchandise your site carries. For products that are
evaluated on the basis of features and that have unambiguous
taxonomies, like electronics and appliances, I've seen very high
click through rates even at the bottom of a 25-category list, and
category navigation is used deep into the catalog. For products that
are scanned primarily by appearance, a top level cut of 6 - 12
general product types, followed by pages that guide primarily through
visuals or in-context scenes that can be rapidly scanned. For products
where customers call the same thing by different names, a dozen or so
sub-categories, with intensive search term mapping effort behind the
scenes.